I'm attaching a file that might help. The settings are in the RenderMan shader, where you need to use an urbermap shader, and link a RenderManTexture with it. The file is loaded through the BitmapReader, you well need to adjust the path in the node to get it to work on your machine.

At this point, texture support in K-3D is very rough, unfortunately. The basics are there in the code, but we need someone to write a more intuitive shader to make it all work nicely.